Wohnhaas was relieved "due to loss of confidence in his ability to effectively lead and carry out his assigned duties," officials said.

At issue is the July 11 breakdown of the Freedom during participation in Rim of the Pacific exercises.

The Freedom, the first in its class built by Lockheed Martin Corp., suffered a leak at its seawater pump mechanical seal, which allowed seawater to enter the engine lube oil system and damage the ship's second main propulsion diesel engine. When the ship returned to port in San Diego after the exercise, engineers determined the engine would either need to be removed and rebuilt, or replaced entirely.

An investigation into the circumstances surrounding the seawater leak and following damage resulted in the commanding officer's relief, officials said.

Wohnhaas, who was commissioned in 1996 and is a surface warfare officer by trade, previously served as the executive officer of the guided-missile destroyer William P. Lawrence and in the Future Ships Requirements Office at Naval Surface Forces Pacific, where he helped to draft the platform wholeness concept of operations for the new DDG 1000 Zumwalt class of destroyer, and led the LCS Fleet Introduction and Sustainability Panel, according to his official biography. He has been temporarily reassigned to Naval Surface Force Forces Pacific, officials said.

The Freedom still awaits repairs in San Diego, and officials said no final decision has been made yet on how to proceed.

Wohnhaas' relief comes seven months after the commander of another Freedom-class LCS, the Fort Worth, was fired due to the circumstances surrounding the ship's breakdown in Singapore in January.

Cmdr. Michael Atwell was relieved March 28 after preliminary results of the investigation into that casualty found lubrication oil was not properly applied to the ship's combining gears during engine start-up. The full results of that investigation have not yet been publicly released.

Five littoral combat ships have sustained engine casualties of varying severity within the last 12 months. In September, the Navy announced a massive engineering review for the entire LCS program, including retraining for all engineering crews, and additional changes possible.

Late last month, Chief of Naval Operations Adm. John Richardson told reporters in Newport, Rhode Island, that the LCS program remained on track and the problems it had were akin to those suffered by other new ship classes in their early days.

"We're learning lessons as it starts up -- in engineering -- as we get this class of ship to sea," Richardson said. "In both hull forms, we're finding things we need to address from an engineering standpoint. We're seeing areas where crew training, preparedness of the crew to operate the ship -- we're learning lessons there as well."